JP2007204551A - Polyurethane foam and sealing material using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyurethane foam exerting good water stop performance and also exerting high adhesiveness to double-sided adhesive tape, and to provide a sealing material using the polyurethane foam. <P>SOLUTION: The polyurethane foam is such as to be obtained by reaction of a feedstock comprising polyols, a polyisocyanate, a catalyst, a foaming agent and a water repellent followed by expansion and curing, and designed to enable its surface to be stuck with a double-sided adhesive tape. The above feedstock also contains a (meth)acrylic polyol as tackifier, whose content being 1-30 pts.mass based on 100 pts.mass of the polyols, and the (meth)acrylic polyol is preferably 20-200 mgKOH/g in hydroxyl number. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polyurethane foam used as a sealing material for an air conditioner such as a damper material for a car air conditioner, and a sealing material using the polyurethane foam.

  Conventionally, as a damper material for a car air conditioner, a laminated product of polyurethane foam having improved water sealability is used in an uncompressed state. The polyurethane foam is added with a water repellent composed of an ester of a polyol and a monocarboxylic acid or a dicarboxylic acid, so that a water sealing property (water repellency) is exhibited (for example, see Patent Document 1). ).

On the other hand, a technique has been proposed in which a plasticizer and a tackifier resin are blended into a polyurethane foam raw material to impart processability and tackiness to the polyurethane foam (see, for example, Patent Document 2). As such tackifying resin, those having a relatively low molecular weight hydrocarbon polymer as a main component and having a softening point of 80 to 120 ° C. are described.
JP-A-8-333432 (pages 2 and 4) JP-T-2001-526722 (Page 2, Page 3 and Page 11)

  However, in the polyurethane foam described in Patent Document 1, since the water repellent is contained in the raw material, the ester as the water repellent moves to the surface, and the adhesiveness on the surface of the foam decreases. . For this reason, when the polyurethane foam is used as a damper material for car air conditioners, if the double-sided adhesive tape is attached to the foam surface, the adhesive force of the double-sided adhesive tape to the foam surface is insufficient, and the damper material for car air conditioners is used. There was a problem that the double-sided pressure-sensitive adhesive tape might peel off from the foam surface before assembling to the car air conditioner.

  On the other hand, the polyurethane foam described in Patent Document 2 is not intended for a sealing material having water repellency, although the tackiness-imparting resin is blended in the raw material to increase the tackiness. It is for molding processing. For this reason, a general hydrocarbon polymer is used as the tackifying resin, and the blending amount of the polyol to the tackifying resin is 5: 1 to 1: 4, that is, the tackifying resin per 100 parts by mass of the polyol. Is 20 to 400 parts by mass. Accordingly, there is a demand for a sealing material such as a damper material for a car air conditioner using a polyurethane foam that exhibits water-repellent properties and has sufficient adhesion to the surface.

  Therefore, the object of the present invention is to provide a polyurethane foam capable of exhibiting good water-stopping properties and at the same time exhibiting excellent adhesion to a double-sided pressure-sensitive adhesive tape, and a sealing material using the same. It is to provide.

  In order to achieve the above object, the polyurethane foam of the invention according to claim 1 is obtained by reacting, foaming and curing a raw material of polyurethane foam containing polyols, polyisocyanates, a catalyst, a foaming agent and a water repellent. A polyurethane foam on which a double-sided pressure-sensitive adhesive tape can be attached. The raw material of the polyurethane foam contains a (meth) acrylic polyol as a tackifier and the content thereof is a polyol. It is 0.7-30 mass parts per 100 mass parts of a kind.

  The polyurethane foam of the invention according to claim 2 is characterized in that, in the invention according to claim 1, the (meth) acrylic polyol has a hydroxyl value of 20 to 200 mgKOH / g.

  A sealing material according to a third aspect of the present invention is characterized in that a double-sided pressure-sensitive adhesive tape is adhered to the surface of the polyurethane foam according to the first or second aspect.

According to the present invention, the following effects can be exhibited.
In the polyurethane foam of the invention described in claim 1, since the raw material contains a water repellent, good water stoppage can be exhibited based on the water repellency. Furthermore, since the raw material of the polyurethane foam contains (meth) acrylic polyol as a tackifier and its content is set to 0.7 to 30 parts by mass per 100 parts by mass of polyols, The adhesiveness with respect to a double-sided adhesive tape can be exhibited based on a (meth) acryl polyol, maintaining the above.

  In the polyurethane foam of the invention according to claim 2, since the (meth) acryl polyol has a hydroxyl value of 20 to 200 mgKOH / g, in addition to the effect of the invention according to claim 1, the double-sided adhesive tape is used. Adhesiveness can be exhibited sufficiently.

  In the sealing material of the invention described in claim 3, the double-sided adhesive tape is adhered to the surface of the polyurethane foam described in claim 1 or claim 2. The effects of the invention according to the present invention can be exhibited, and it can be suitably used as a sealing material for air conditioning equipment.

In the following, embodiments that are considered to be the best of the present invention will be described in detail.
The polyurethane foam in the present embodiment (hereinafter also simply referred to as a foam) is one in which a double-sided adhesive tape can be attached to the surface. The polyurethane foam has a (meth) acrylic polyol as a tackifier on the raw material of the polyurethane foam containing polyols, polyisocyanates, catalyst, foaming agent and water repellent. ˜30 parts by mass, obtained by reacting, foaming and curing the raw material. This polyurethane foam is used as a sealing material with a double-sided adhesive tape attached to the surface thereof. The sealing material is used, for example, as a sealing material for an air conditioner represented by a damper material for a car air conditioner.

First, the raw material of a polyurethane foam is demonstrated in order.
(Polyols)
As the polyols, polyester polyol, polyether polyol or polyether ester polyol may be used alone or as a mixture. Polyester polyol from the viewpoint of excellent compatibility with (meth) acrylic polyol as water repellent and tackifier. Is preferred.

  As polyester polyols, in addition to condensation polyester polyols obtained by reacting polycarboxylic acids such as adipic acid and phthalic acid with polyols such as ethylene glycol, diethylene glycol, propylene glycol and glycerin, lactone polyester polyols and polycarbonate systems A polyol is used.

  As the polyether polyol, a polyether polyol composed of a polymer obtained by addition polymerization of propylene oxide and ethylene oxide to a polyhydric alcohol, a modified product thereof, and the like are used. Examples of the modified product include those obtained by adding acrylonitrile or styrene to the polyether polyol, or those obtained by adding both acrylonitrile and styrene. Here, the polyhydric alcohol is a compound having a plurality of hydroxyl groups in one molecule, and examples thereof include glycerin and dipropylene glycol.

  Specific examples of polyether polyols include triols obtained by addition polymerization of propylene oxide to glycerin and addition polymerization of ethylene oxide, and diols obtained by addition polymerization of propylene oxide to dipropylene glycol and addition polymerization of ethylene oxide. .

  The polyether ester polyol is a compound obtained by reacting a polyoxyalkylene polyol with a polycarboxylic acid anhydride and a compound having a cyclic ether group. Examples of polyoxyalkylene polyols include polyethylene glycol, polypropylene glycol, and propylene oxide adducts of glycerin. Examples of polycarboxylic acid anhydrides include succinic acid, adipic acid, phthalic acid, trimellitic acid, and other anhydrides. Examples of the compound having a cyclic ether group include ethylene oxide and propylene oxide. The order in which these three components are reacted is not particularly limited. For example, a method in which three components are reacted at the same time, a method in which a compound having a cyclic ether group is blown into polyoxyalkylene polyol and polycarboxylic acid anhydride, and a reaction in which a part of polyoxyalkylene polyol and polycarboxylic acid anhydride is reacted. And a method of reacting the compound having a cyclic ether group with the remainder of the polycarboxylic acid anhydride.

These polyols can change the number of functional groups and the hydroxyl value of the hydroxyl group by adjusting the kind of raw material component, the molecular weight, the degree of condensation, and the like.
(Polyisocyanates)
Next, polyisocyanates to be reacted with polyols are compounds having a plurality of isocyanate groups, specifically, tolylene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate ( NDI), triphenylmethane triisocyanate, xylylene diisocyanate (XDI), hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate, isophorone diisocyanate (IPDI), and modified products thereof.

The isocyanate index (index) of the polyisocyanates is preferably set in the range of 100 to 130. When the isocyanate index is less than 100, physical properties such as hardness and tensile strength of the polyurethane foam deteriorate, and when it exceeds 130, the crosslinking density of the polyurethane foam becomes too high. Here, the isocyanate index represents the equivalent ratio of the isocyanate group of the polyisocyanate to the active hydrogen group such as water as a foaming agent and the hydroxyl group of the polyol in percentage.
(Foaming agent)
The foaming agent is for foaming a polyurethane resin to form a polyurethane foam. For example, dichloromethane (methylene chloride), pentane, cyclopentane, hexane, cyclohexane, carbon dioxide and the like are used in addition to water. Of these foaming agents, water is preferable because it can react quickly with polyisocyanates to generate sufficient carbon dioxide gas and can be handled easily. The blending amount of the foaming agent is preferably 1 to 5 parts by mass per 100 parts by mass of polyols. When the blending amount of the foaming agent is less than 1 part by mass, foaming becomes insufficient and it becomes difficult to obtain a low-density foam. On the other hand, when it exceeds 5 parts by mass, foaming becomes excessive and physical properties such as hardness and tensile strength of the foam are lowered.
(catalyst)
The catalyst is mainly for accelerating the urethanization reaction between polyols and polyisocyanates. Specific examples of the catalyst include tertiary amines such as triethylenediamine, N, N-dimethylaminoethanol, N, N ′, N′-trimethylaminoethylpiperazine, and organometallic compounds such as tin octylate (tin octoate). Acetate, alkali metal alcoholate, etc. are used alone or in combination. The compounding amount of the catalyst is preferably 0.5 to 1.5 parts by mass per 100 parts by mass of polyols. When the compounding amount of the catalyst is less than 0.5 parts by mass, the progress of the urethanization reaction and the like is not sufficient, and the mechanical properties of the foam tend to decrease. On the other hand, when the amount exceeds 1.5 parts by mass, the progress of the urethanization reaction is excessive, and the formation of the foam is biased.
(Water repellent)
The water-repellent agent is for causing the polyurethane foam to exhibit water-stopping property based on water repellency, and is an ester of a polyol and a monocarboxylic acid having 12 or more carbon atoms, a polyol, a monocarboxylic acid having 12 or more carbon atoms and a carbon number. Esters with 8 or more dicarboxylic acids are used. Examples of the polyol include dihydric or higher polyols, that is, polyethylene glycol having a molecular weight of 1000 to 4000, polypropylene glycol, and glycol of ethylene-propylene copolymer. Examples of the monocarboxylic acid having 12 or more carbon atoms include lauric acid, palmitic acid, stearic acid, and oleic acid. Examples of the dicarboxylic acid having 8 or more carbon atoms include azelaic acid, sebacic acid, and dimer acid. Of these water repellents, compounds having good water repellency are preferred because molecules such as diesters of dimer acid are bulky and have a large contact angle.
(Tackifier)
The tackifier is for imparting adhesiveness to the double-sided adhesive tape to the polyurethane foam. The pressure-sensitive adhesive used for the double-sided pressure-sensitive adhesive tape contains a (meth) acrylic polymer obtained by polymerizing a monomer mixture such as 2-ethylhexyl acrylate and butyl acrylate. As the tackifier, (meth) acrylic polyol is used. The (meth) acryl polyol has a hydroxyl value of preferably 20 to 200 mgKOH / g, more preferably 40 to 120 mgKOH / g, and particularly preferably 60 to 100 mgKOH / g. When the hydroxyl value is less than 20 mgKOH / g, the resulting polyurethane foam has a low crosslinking density and tends to be soft and mechanical strength is lowered. On the other hand, when the hydroxyl value exceeds 200 mgKOH / g, the resulting polyurethane foam has a high crosslinking density and tends to become brittle.

  This (meth) acryl polyol can be obtained by copolymerizing a hydroxyl group-containing (meth) acrylate and another polymerizable monomer. At this time, although the usage-amount of a hydroxyl-containing (meth) acrylate is suitably determined so that the hydroxyl value of a (meth) acryl polyol may become the said range, it is 10-10 normally with respect to 100 mass parts of total amounts of a raw material monomer. The amount is desirably 50 parts by mass.

  Examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, and diethylene glycol mono (meth) acrylate. It is done. Examples of other polymerizable monomers include alkyl (meth) acrylates, other (meth) acrylates, styrene monomers, and other vinyl monomers.

  Alkyl (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and stearyl (meth). An acrylate etc. are mentioned. Examples of other (meth) acrylates include cyclohexyl (meth) acrylate, diethylene glycol mono (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, and glycidyl (meth) acrylate.

  Examples of styrenic monomers include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene and octyl styrene; alkyl styrene; fluorostyrene, chlorostyrene Halogenated styrenes such as bromostyrene, dibromostyrene and iodostyrene; nitrostyrene, acetylstyrene and methoxystyrene.

  Other vinyl monomers include vinyl pyridine, vinyl pyrrolidone, vinyl carbazole, divinyl benzene, vinyl acetate and acrylonitrile; conjugated diene monomers such as butadiene, isoprene and chloroprene; vinyl halides such as vinyl chloride and vinyl bromide; vinylidene chloride And vinylidene halides such as

These monomers are appropriately selected so that the hydroxyl value of the (meth) acryl polyol falls within the above range, and one kind can be used alone, or two or more kinds can be used in combination.
Such a (meth) acryl polyol can be produced by a usual polymerization method such as a solution polymerization method. For example, it can be produced by dissolving or dispersing the monomer in an organic solvent and reacting the solution or dispersion in a reactor substituted with an inert gas such as nitrogen gas. Examples of the organic solvent used here include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as n-hexane, esters such as ethyl acetate and butyl acetate, n-propyl alcohol, and i-propyl. Examples thereof include aliphatic alcohols such as alcohol, and ketones such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

  The polymerization reaction is performed by heating in the presence of a polymerization initiator. Examples of the polymerization initiator include azobisisobutyronitrile, benzoyl peroxide, di-tert-butyl peroxide, cumene hydroperoxide, and the like. This polymerization initiator is usually used in an amount of 0.01 to 10 parts by mass with respect to 100 parts by mass of the total amount of raw material monomers. The polymerization reaction temperature is usually 50 to 90 ° C., and the polymerization reaction time is usually 2 to 20 hours, preferably 4 to 12 hours. The (meth) acrylic polyol produced under such polymerization conditions can be used after being separated from the organic solvent, but the (meth) acrylic polyol produced is used in a state dissolved or dispersed in the organic solvent. It is simple and preferable.

  The weight average molecular weight of the (meth) acryl polyol is preferably 1000 to 3000. When this mass average molecular weight is less than 1000, the resulting polyurethane foam tends to have a high crosslinking density, and the foam may be brittle. On the other hand, when the mass average molecular weight exceeds 3000, the polyurethane foam tends to have a low crosslinking density, and the mechanical properties of the foam tend to be lowered.

  Here, since the (meth) acrylic polyol has a hydroxyl group, it reacts with the polyisocyanates and is incorporated into the polyurethane skeleton. In addition, although (meth) acryl polyol is a kind of polyols, it is used as a tackifier and is not included in the polyols in calculating the content.

About the above (meth) acryl polyol, content in the raw material of a polyurethane foam needs to be 0.7-30 mass parts per 100 mass parts of polyols. When the content of the (meth) acrylic polyol is less than 0.7 parts by mass, the content of the (meth) acrylic polyol as a tackifier is too small. It becomes impossible to express. On the other hand, when the content exceeds 30 parts by mass, since the content of the (meth) acryl polyol is excessive, the balance of the raw material composition is deteriorated and foaming is hindered to obtain the desired foam. Can not be.
(Foam stabilizer)
The foam stabilizer is preferably blended in the raw material of the polyurethane foam in order to smoothly foam, and as the foam stabilizer, those generally used in the production of polyurethane foam can be used. Specific examples of the foam stabilizer include silicone compounds, anionic surfactants such as sodium dodecylbenzenesulfonate and sodium lauryl sulfate, polyether siloxane, and phenolic compounds. Among these, a linear or branched polyether-siloxane copolymer is preferable, and a linear polysiloxane-polyoxyalkylene copolymer having a low foam regulating power is particularly preferable in order to improve the connectivity. The blending amount of the foam stabilizer is preferably 0.5 to 2.5 parts by mass per 100 parts by mass of polyols. When the blending amount is less than 0.5 parts by mass, the foam regulating action during foaming of the polyurethane foam raw material is not sufficiently exhibited, and it becomes difficult to obtain a good foam. On the other hand, when it exceeds 2.5 parts by mass, the foam regulating action becomes stronger and the cell connectivity tends to be lowered.
(Other ingredients)
In addition to the raw material of the polyurethane foam, a crosslinking agent, an antioxidant, a filler, a stabilizer, a colorant, a flame retardant, a plasticizer, and the like can be blended as necessary.

Next, a method for producing a polyurethane foam using the above-mentioned polyurethane foam raw material will be described.
A polyurethane foam is produced by reacting the raw material of the polyurethane foam to be foamed and cured, but the reaction at that time is complicated, and basically the following reaction is mainly performed. That is, addition polymerization reaction of polyols and polyisocyanates (urethanization reaction, resinification reaction), foaming (foaming) reaction of polyisocyanates with water as a blowing agent, and reaction products of these and polyisocyanates And crosslinking (curing) reaction. When producing a polyurethane foam, a one-shot method in which a polyol and a polyisocyanate are directly reacted, or a polyol and a polyisocyanate are reacted in advance to obtain a prepolymer having an isocyanate group at the terminal, Both of the prepolymer methods in which polyols are reacted with it are employed. Then, a foaming agent is mixed in a mixed liquid of polyols and polyisocyanates, or a mixed liquid of prepolymer and polyols, and (Metal as a foam stabilizer, catalyst, water repellent and tackifier is added. ) Acrylic polyol is added and stirred and mixed to react, foam and cure the raw materials.

  As the foamed form, mold foaming is possible, but slab foaming is preferred from the viewpoint of ease of foaming and productivity. The slab foaming is performed by discharging the agitated and mixed raw material onto a belt conveyor, and the raw material reacts at room temperature and atmospheric pressure while the belt conveyor moves and spontaneously foams. Then, a slab foam is obtained by hardening (curing) in a drying furnace. The obtained polyurethane foam is cut into a desired shape and used.

The polyurethane foam obtained in this way can exhibit a sufficient water-stopping property without water leakage due to the inclusion of the water repellent. In addition, since the foam contains (meth) acrylic polyol as a tackifier, the 90 ° peel strength when a double-sided adhesive tape is attached to the foam is, for example, 17 to 23 N / 25 mm Can be obtained. Preferably the apparent density of the foam is 25 to 60 kg / ^{m 3,} more preferably 35~50kg / ^{m 3.} When the apparent density was less than 25 kg / m ³ , the voids of the foam increased and the water repellency was lowered. When the apparent density exceeded 60 kg / m ³ , the foam became too dense and used as a sealing material. Sometimes the mounting workability decreases and the manufacturing cost also increases.

  Next, the sealing material is configured by adhering one side of a double-sided pressure-sensitive adhesive tape to the surface of the polyurethane foam. Since the polyurethane foam has excellent surface adhesion as described above, the double-sided pressure-sensitive adhesive tape is firmly bonded to the foam. Then, the other surface of the double-sided pressure-sensitive adhesive tape is used by being adhered to the adherend. This sealing material is used as a sealing material for air conditioning equipment such as a damper material for a car air conditioner.

  Now, the operation of the present embodiment will be described. The raw material of the polyurethane foam contains a water repellent in addition to polyols, polyisocyanates, a catalyst and a foaming agent. As this water repellent, a hydrophobic higher ester having a large number of carbon atoms or the like is used, and the higher ester migrates to the surface of the foam to exhibit good water repellency on the surface of the foam. And the raw material of a polyurethane foam contains 1-30 mass parts of (meth) acryl polyol per 100 mass parts of polyols as a tackifier. This (meth) acryl polyol has good compatibility with the raw material of polyurethane foam such as a catalyst, so that it is uniformly dispersed in the raw material and foaming is performed well, and the foam is based on the properties of (meth) acryl polyol. Adhesiveness is imparted to the surface. In this case, since the (meth) acrylic polyol is incorporated into the skeleton of the polyurethane foam, the adhesiveness can be continuously exhibited in a stable state. In addition, (meth) acrylic polyol is a component of the same quality as the acrylic polymer that is a tackifier in the double-sided pressure-sensitive adhesive tape that is bonded to the foam. Can be improved.

The effects exhibited by the above embodiment will be described collectively below.
-In the polyurethane foam of this embodiment, since the water repellent is contained in the raw material, favorable water stoppage can be exhibited based on the water repellency. Furthermore, since the raw material of the polyurethane foam contains (meth) acrylic polyol as a tackifier and the content thereof is 1 to 30 parts by mass per 100 parts by mass of polyols, Excellent adhesion to the double-sided pressure-sensitive adhesive tape can be exhibited.

-Since the said (meth) acryl polyol has a hydroxyl value of 20-200 mgKOH / g, it can fully exhibit the adhesiveness in the foam surface.
-Since the sealing material is configured by adhering a double-sided adhesive tape to the surface of the polyurethane foam, the effect of the polyurethane foam can be exerted, and it is suitable as a sealing material for air conditioning equipment. Can be used for

Hereinafter, the embodiment will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples.
(Examples 1-10 and Comparative Examples 1-7)
First, raw materials for polyurethane foams comprising polyols, polyisocyanates, foaming agents, foam stabilizers, catalysts, water repellents and tackifiers used in Examples and Comparative Examples are shown below.

Polyol A: Polyester polyol, number of functional groups 3, hydroxyl value 56.1 (mgKOH / g), molecular weight 3000, trade name manufactured by Sanyo Chemical Industries, AH-405.
Polyol B: Polyether ester polyol, number of functional groups 3, hydroxyl value 56.1 (mgKOH / g), molecular weight 3000, trade name L-50 manufactured by Mitsui Takeda Chemical Co., Ltd.

Water repellent: Distearyl dimer acid Foaming agent (water): Tap water.
Amine catalyst: N, N-dimethylaminoethanol Metal catalyst: stannous octoate (stannas octoate)
Foam stabilizer: Silicone foam stabilizer, trade name, SH-193, manufactured by Toray Dow Corning Co., Ltd.

  Polyisocyanate: 80/20 (mass ratio) mixture of 2,4-TDI / 2,6-TDI, trade name T-80 manufactured by Nippon Polyurethane Industry Co., Ltd. This polyisocyanate was blended so that the isocyanate index was 110.

  Acrylic polyol 1: Acrylic polyol mainly composed of 2-ethylhexyl acrylate as tackifier, hydroxyl value 83 ± 2 (mgKOH / g), mass average molecular weight of about 2700, trade name manufactured by Soken Chemical Co., Ltd., UT- 2001.

  Acrylic polyol 2: Acrylic polyol mainly composed of n-butyl acrylate as a tackifier, hydroxyl value 89 ± 2 (mgKOH / g), mass average molecular weight of about 2200, trade name manufactured by Soken Chemical Co., Ltd., UMB- 2005.

  And each of these raw materials was mix | blended with the compounding quantity shown in Table 1 and Table 2, and the raw material of the polyurethane foam in each Example and a comparative example was prepared. Thereafter, the raw materials of these polyurethane foams are poured into foam containers of 500 mm in length, width and depth, foamed at normal temperature and atmospheric pressure, and then cured (crosslinked) by passing through a heating furnace. A soft slab foam was obtained. During the process, the foamed state was visually observed. The obtained soft slab foam was cut out to produce a sheet-like polyurethane foam.

  In this case, Comparative Example 1 shows an example in which a water repellent and a tackifier are not blended (blank test). Comparative Example 2 shows an example in which no tackifier is added. Comparative Example 3 shows an example in which no tackifier is blended and the blending amounts of polyol A and polyol B are changed. In Comparative Example 4, the blending amount of acrylic polyol 1 as a tackifier is less than 1 part by weight with respect to 100 parts by weight of polyol. In Comparative Example 5, the blending amount is 10 parts by weight with respect to 100 parts by weight of polyol. An example that goes beyond the division is shown. Comparative Example 6 shows an example in which the blending amount of acrylic polyol 2 as a tackifier is less than 1 part by weight with respect to 100 parts by weight of polyol. In Comparative Example 7, the blending amount is 10 parts by weight with respect to 100 parts by weight of polyol. An example that goes beyond the division is shown.

With respect to the obtained polyurethane foam, the apparent density, hardness, waterstop and peel strength were measured according to the following measuring methods. The results are shown in Tables 1 and 2.
(Measuring method)
Apparent density (kg / m ³ ): Measured according to JIS K7222 (1999).

Hardness (N): Measured according to JIS K6400-2 (D method).
Water stoppage: A state in which a U-shaped test piece having a cross section with a thickness and a width of 15 mm is both compressed by 50% with two acrylic resin plates from both sides in the thickness direction by punching (thus, the thickness is 7.5 mm), water was poured from the U-shaped bottom inner surface to a height of 100 mm, and the time until water oozed out from the U-shaped bottom outer surface was measured. The case where water did not ooze out after 24 hours was marked with ◯, and the case where water oozed out was marked with x.

  Peel strength (N / 25 mm): Measured according to JIS Z1528 (90 ° peel). Double-sided pressure-sensitive adhesive tape A is a double-sided pressure-sensitive adhesive tape whose base material is an acrylic resin, a product name manufactured by Nitto Denko Corporation, 501L. Double-sided pressure-sensitive adhesive tape B is a double-sided pressure-sensitive adhesive tape whose base material is synthetic rubber, trade name, manufactured by Dainippon Ink & Chemicals, Inc., # 8840ER.

表１に示した結果から、実施例１〜１０においては、ポリウレタン発泡体の原料に撥水剤を含むとともに、粘着性付与剤としてアクリルポリオール１又はアクリルポリオール２をポリオール１００質量部当たり１〜３０質量部含むことから、止水性が良好であると同時に、剥離強度も優れていた。さらに、両面粘着テープＡ及びＢでの剥離強度の差は大きくないことから、両面粘着テープの種類にかかわらず、接着性を高めることができた。

From the result shown in Table 1, in Examples 1-10, while including a water repellent in the raw material of a polyurethane foam, acrylic polyol 1 or acrylic polyol 2 is used as tackifier 1-30 per 100 mass parts polyol. Since it contains a mass part, the water-stopping property is good and the peel strength is also excellent. Furthermore, since the difference in peel strength between the double-sided pressure-sensitive adhesive tapes A and B was not large, the adhesiveness could be improved regardless of the type of the double-sided pressure-sensitive adhesive tape.

表２に示した結果から、比較例１では、ポリウレタン発泡体の原料に撥水剤が含まれていないため止水性が不良であるとともに、粘着性付与剤であるアクリルポリオールも含まれていないため剥離強度も不十分であった。比較例２及び３では、アクリルポリオールが含まれていないため剥離強度が低い結果であった。比較例４及び６では、アクリルポリオールの配合量が少なかったため、剥離強度が不十分であった。比較例５及び７では、アクリルポリオールの配合量を増加させた結果、発泡がやや不良になる上に、止水性が悪化した。

From the results shown in Table 2, in Comparative Example 1, since the water-repellent agent is not included in the raw material of the polyurethane foam, the water stoppage is poor, and the acrylic polyol that is a tackifier is not included. The peel strength was also insufficient. In Comparative Examples 2 and 3, since acrylic polyol was not included, the peel strength was low. In Comparative Examples 4 and 6, since the blending amount of the acrylic polyol was small, the peel strength was insufficient. In Comparative Examples 5 and 7, as a result of increasing the blending amount of the acrylic polyol, the foaming was slightly poor and the water stoppage was deteriorated.

In addition, the said embodiment can also be changed and actualized as follows.
-As a tackifier, a methacryl polyol obtained by copolymerizing a hydroxyl group-containing methacrylate and another polymerizable monomer can be used.

  ・ In addition to the (meth) acrylic polyol as a tackifier, natural resins such as rosin and polyterpene that are generally used as tackifiers, or synthetic resins such as petroleum resins, epoxy resins, and phenol formaldehyde resins are used. It is also possible to mix | blend with the raw material of a polyurethane foam.

  -As a tackifier, the acrylic polymer which has a carboxyl group can also be mix | blended in addition to the said (meth) acryl polyol. In that case, when the pH of the raw material shifts to the acidic side, it is preferable to adjust the raw material to the alkali side by blending an alkaline pH adjuster such as sodium hydrogen carbonate in order to perform foaming well.

Further, the technical idea that can be grasped from the embodiment will be described below.
The polyurethane foam according to claim 1 or 2, wherein the (meth) acryl polyol as the tackifier has a mass average molecular weight of 1000 to 3000. When constituted in this way, in addition to the effect of the invention according to claim 1 or claim 2, the mechanical properties of the foam can be improved.

  The polyurethane foam according to claim 1 or 2, wherein the polyol is a mixture of a polyester polyol and a polyether ester polyol. When constituted in this way, in addition to the effects of the invention according to claim 1 or claim 2, the compatibility of the polyols with respect to the water repellent and the tackifier can be enhanced, and the foaming is performed well. be able to.

  ・ Polyurethane foam materials including polyols, polyisocyanates, catalysts, foaming agents and water repellents are reacted, foamed and cured to prepare polyurethane foam, and double-sided adhesive tape is applied to the surface of the polyurethane foam. A method for producing a polyurethane foam that can be attached, wherein the raw material of the polyurethane foam contains (meth) acrylic polyol as a tackifier, and the content thereof is 0.7 to 100 parts by mass of polyols. A method for producing a polyurethane foam, which is 30 parts by mass. According to this production method, it is possible to easily produce a polyurethane foam that can exhibit good water-stopping properties and at the same time exhibit excellent adhesion to a double-sided pressure-sensitive adhesive tape.

Claims (3)

A polyurethane foam obtained by reacting, foaming and curing a polyurethane foam raw material containing polyols, polyisocyanates, catalyst, foaming agent and water repellent, and capable of adhering a double-sided adhesive tape on its surface. ,
The polyurethane foam has a (meth) acrylic polyol as a tackifier, and the content thereof is 0.7 to 30 parts by mass per 100 parts by mass of polyols. The polyurethane foam according to claim 1, wherein the (meth) acrylic polyol has a hydroxyl value of 20 to 200 mgKOH / g. A sealing material comprising a polyurethane foam according to claim 1 or 2 and having a double-sided adhesive tape attached to the surface thereof.